In an emergency such as a collision, an air bag device which is disposed in front of a seat of a vehicle deploys an air bag by gas spouted from an inflator to protect an occupant.
FIG. 5 is a sectional view showing a conventional air bag device for protecting a driver and FIG. 6 is an enlarged sectional view of an A-portion of FIG. 5.
In these drawings, reference numeral 10 designates an air bag mounting plate, which is referred to as a retainer. The retainer 10 has an inflator mounting opening 12 in the center thereof where an inflator 14 is mounted.
An air bag 16 is provided with a receiving opening 18 for receiving an upper portion of the inflator 14. The receiving opening 18 is disposed around the periphery of the mounting opening 12. The periphery of the receiving opening 18 of the air bag 16 is held between a retaining ring 20 and the periphery of the mounting opening 12. A back of the retainer 10 is in contact with a flange 14f of the inflator 14. The retaining ring 20, the air bag 16, the retainer 10, and the flange 14f are pierced with rivets 24 so as to fix the air bag 16 to the retainer 10.
The air bag 16 is folded and is covered by a module cover 22. The module cover 22 is broken by a pressure of expansion of the air bag 16 when the air bag 16 is deployed by gas spouted from the inflator 14.
In the aforementioned mounting structure for an air bag of the conventional air bag device, the retaining ring 20 is required to hold the periphery of the receiving opening of the air bag, increasing cost for parts by this part.